1. Field of the Invention
This invention relates to a common-rail fuel injection system for an engine.
2. Description of the Related Art
Common-rail fuel injection systems for internal combustion engines such as diesel engines, include a high-pressure tubing which forms a pressure accumulator referred to as "a common rail". In general, the fuel injection systems of this type also include a high-pressure fuel supply pump for feeding high-pressure fuel to the common rail, and fuel-injection solenoid valves (fuel injectors) for selectively allowing the high-pressure fuel to flow from the common rail into engine cylinders.
In the case of automotive engines, the pressure of fuel injected into the engine cylinders has been increased to meet the emission regulations. The increased fuel injection pressure has necessitated an increase in the size of fuel-injection solenoid valves (fuel injectors).
However a compact engine arrangement, it is desirable to decrease the spaces occupied by fuel-injection solenoid valves (fuel injectors;). A region near an engine body or an engine block is required to accommodate various parts, such as inlet valves and outlet valves, of a system having a conventional configuration. Also, in this regard, it is desirable to decrease the spaces occupied by the fuel-injection solenoid valves (fuel injectors).